NEMA_EvaluatingWater-DamagedElectricalEquipment

8/3/2019 NEMA_EvaluatingWater-DamagedElectricalEquipment

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E VALUATING

W ATER -DAMAGED

ELECTRICAL EQUIPMENT

N ATIONAL ELECTRICAL M ANUFACTURERS A SSOCIATION

1300 NORTH 17TH STREET, SUITE 1752

R OSSLYN, VIRGINIA 22209

703 841-3200

703 841-5900 FAX

WWW.NEMA .ORG



© Copyright 2006 by the National Electrical Manufacturers Association. Page 1

Evaluating Water-Damaged Electrical Equipment

1 USE OF THIS PUBLICATION

This publication provides information on how to evaluate electrical equipment that has been exposed towater through flooding, fire fighting activities, hurricanes, etc. It is designed for use by suppliers,installers, inspectors and users of electrical products.

Electrical equipment exposed to water can be extremely hazardous if reenergized without properreconditioning or replacement. Reductions in integrity of electrical equipment due to moisture can affectthe ability of the equipment to perform its intended function. Damage to electrical equipment can alsoresult from flood waters contaminated with chemicals, sewage, oil and other debris, which will affect theintegrity and performance of the equipment. Ocean water and salt spray can be particularly damagingdue to the corrosive and conductive nature of the salt water residue.

Distributors of electrical equipment should not supply any inventory that has been subjected to waterdamage. This can lead to damaged equipment still being used and creating a hazard to individuals or

property.

2 TO CONTACT THE MANUFACTURER

Working knowledge of electrical systems and of the equipment in question is required to evaluatedamage due to contact with water. The original manufacturer of the equipment should be contacted ifany questions arise or specific recommendations are needed. In many cases, replacement will benecessary.

After consultation with the manufacturer, some larger types of electrical equipment may bereconditioned by properly trained personnel. The potential to recondition the equipment may vary withthe nature of the electrical function, the degree of flooding, the age of the equipment, and the length oftime the equipment was exposed to water.

Attempts to recondition equipment without consulting the manufacturer can result in additional hazardsdue to the use of improper cleaning agents, which can further damage the equipment (see National

Electrical Code Section 110.11 FPN No.2) or due to improper reconditioning techniques.

NEMA member companies are committed to safety. For specific contacts within these manufacturingfirms, call or write:

National Electrical Manufacturers Association1300 North 17th Street, Suite 1752Rosslyn, Virginia 22209Telephone: (703) 841-3236Fax: (703) 841-3336

ATTN: Vince Baclawskiemail: [email protected]




3 ELECTRICAL EQUIPMENT REPLACEMENT/RECONDITIONING REQUIREMENTS

The table shown below provides the requirements and recommendations associated with variouscategories of electrical equipment that have been subjected to water damage. Where it is shown thatthe equipment “may be reconditioned” it is critical that the manufacturer of the equipment be contactedfor specific guidance.

EquipmentReplace

Equipment

May beReconditioned(Contact the

manufacturer.)

Additional Standards Reference(if available)

ELECTRICAL DISTRIBUTION EQUIPMENT (refer to 4.1)

Molded case circuit breakers X

Low voltage fuses X

Enclosed switches X

NEMA KS 1-2001, Enclosed and Miscellaneous Distribution Equipment Switches (600 Volts Maximum), para 5.1,5.1.2

Busway(mylar wrapped bars)

X

Busway(powder coated bars)

X

NEMA BU 1.1-2000, General Instructions for Handling, Installation, Operation, and Maintenance of Busway Rated 600 Volts or Less , para 3.4.4, 9.2.4.2

Panelboards X

NEMA PB 1.1-2002, General Instructions for Proper Installation, Operation, and Maintenance of Panelboards Rated 600 Volts or Less , para. 10.3, 10.8.3, 10.8.4

Switchboards X

NEMA PB 2.1-2002, General Instructions for Proper Handling, Installation,Operation and Maintenance of Deadfront Distribution Switchboards Rated 600 Volts or Less , para. 11.3.1.3, 11.10

MOTOR CONTROL EQUIPMENT (refer to 4.2)

Adjustable speed drives X

Components containingsemiconductors andtransistors

X

Electronically controlled andsolid state contactors andstarters

X

Overload relays XManual and magneticcontrollers

X

Motor control centers X

POWER EQUIPMENT (refer to 4.3)

Electronic trip units of LVpower breakers

X

High-voltage circuit breakers(AC)

X

Low voltage power circuitbreakers

X

Protective relays, meters,and current transformers

X

Low voltage switchgear X

Medium voltage switchgear X




EquipmentReplace

Equipment

May beReconditioned(Contact the

manufacturer.)

Additional Standards Reference(if available)

TRANSFORMERS (refer to 4.4)

All dry-type transformersregardless of kVA ratings

X

All dry type control circuittransformers

X

Liquid-filled transformers X

(Analysis of theinsulating mediumis required forevaluation of thisequipment.)

Cast-resin transformers X

WIRE, CABLE AND FLEXIBLE CORDS (refer to 4.5)

Wire or cable listed for drylocations (such as NM-B)

X

Wire or cable that is suitablefor wet locations

(Provided the ends of thewire or cable have not beenexposed to water and thewire is not damaged.)

X

AFCIs, GFCIs, SURGE PROTECTIVE DEVICES AND WIRING DEVICES (refer to 4.6)

Arc Fault Circuit Interrupters

(AFCI) and Ground FaultCircuit Interrupters (GFCI)

X

Surge Protective Devices(transient voltage surgesuppressors, surgearresters, lightning arresters)

X

Wiring Devices (switches,receptacles, dimmers, etc.)

X

OTHER DEVICES

Cable Tray (refer to 2.7) X

(Replace damagedlabels.)

Fire Pump Controllers

X

NEMA ICS 15-1999 (R2004), Instructions for the Handling, Installation, Operation,and Maintenance of Electric Fire Pump Controllers Rated Not More Than 600V

Luminaires (lighting fixtures)(refer to 4.8)

X

Motors (refer to 4.9) X ANSI/IEEE 43-2000, A2 and A3

Signaling, Protection andCommunications systems(refer to 4.10)

X




4 THE HAZARDS ASSOCIATED WITH WATER-DAMAGED ELECTRICAL EQUIPMENT

4.1 Electrical Distribution Equipment

Electrical distribution equipment usually involves switches and low-voltage protective components suchas molded case circuit breakers and fuses within assemblies such as enclosures, panelboards andswitchboards. These assemblies can be connected to electrical distribution systems using variouswiring methods.

The protective components are critical to the safe operation of distribution circuits. Their ability toprotect these circuits is adversely affected by exposure to water and to the minerals, contaminants, andparticles, which may be present in the water. In molded case circuit breakers and switches, suchexposure can affect the overall operation of the mechanism through corrosion, through the presence offoreign particles, and through loss of lubrication. The condition of the contacts can be affected and thedielectric insulation capabilities of internal materials can be reduced. Further, some molded case circuitbreakers are equipped with electronic trip units and the functioning of these trip units can be impaired.Water may affect the filler material of fuses and will degrade the insulation and interruption capabilities.

Distribution assemblies contain protective components together with the necessary support structures,

buswork, wiring, electromechanical or electronic relays and meters. Exposure to water can causecorrosion and insulation damage to all of these areas. In the case of exposure of distributionassemblies to water, contact the manufacturer before further action is taken.

4.2 Motor Control Equipment

Motor circuits include motor control devices such as motor starters and contactors, together withovercurrent protection components such as overload relays, circuit breakers, and fuses oftenassembled into motor control panels and motor control centers as well as individual enclosures. Motorcontrol centers contain both control and protective components together with support structures,buswork and wiring.

The protective components are critical to the safe operation of motor circuits and their ability to protect

these circuits is adversely affected by exposure to water, and to the minerals, contaminants, andparticles, which may be present in the water. For molded case circuit breakers, such exposure canaffect the overall operation of the mechanism through corrosion, through the presence of foreignparticles, and through loss of lubrication. The condition of the contacts can be affected and thedielectric insulation capabilities of internal materials can be reduced. Further, some molded case circuitbreakers are equipped with electronic trip units, and the functioning of these trip units can be impaired.Water may affect the filler material of fuses and will degrade the insulation and interruption capabilities.

Corrosion, loss of lubrication and insulation quality can also be expected in contactors and starters.Solid-state motor controllers and those electromechanical contactors or starters with integral electroniccircuitry will be more severely affected by water.

4.3 Power Equipment

Power equipment involves low voltage or medium voltage protective devices within an overallswitchgear assembly. The assembly may also contain cabling, buswork with appropriate insulators,current transformers, electromechanical or electronic relays, and metering.Reliable operation of the protective devices is vital to system safety. These devices can be adverselyaffected by water. In the case of low voltage and medium voltage circuit breakers and switches, theoperation of the mechanism can be impaired by corrosion, by the presence of particles such as silt, andby the removal of lubricants. The dielectric properties of insulation materials and insulators will degradeand, for air circuit breakers, the condition of the contacts can be affected. Further, low voltage powercircuit breakers usually incorporate electronic trip units; the functioning of these units will be impaired.Similarly, the functionality of electronic protective relays and meters can be impaired.




Water may affect the filler material of fuses and will degrade the insulation and interruption capabilities.

Power circuit breakers and medium voltage breakers are designed to be maintainable with thepossibility of replacing contacts in air circuit breakers. Therefore, it maybe possible to reuse such circuitbreakers provided the refurbishing is performed in close consultation with the manufacturer. Thisincludes cleaning and drying techniques, lubrication advice, and thorough testing prior to thereapplication of power. However, discard and replace the electronic trip units of low voltage powercircuit breakers, and electronic protective relays and meters in any power equipment.

Replace fusible units of fused equipment. The remainder of the apparatus may be suitable forrefurbishing in close consultation with the manufacturer.

In all cases, great attention must be paid to the thorough cleaning, drying, and testing of insulators andinsulation material.

The power equipment can be expected to contain additional electronic units such as solid state relays.These units can also be vital to the correct functioning of the protective device, and great care isneeded in the cleaning and testing of such units. A first recommendation is to return the devices to themanufacturer. If this is not possible, the manufacturer should be consulted on the correct selection of

cleaning agents that remove impurities without damaging the conformal coating. The manufacturer shallalso be contacted for the specific testing required of sophisticated electronic equipment containing, forexample, microprocessors.

The overall power equipment assembly (switchgear) may be able to be reconditioned provided carefulsteps are taken in the cleaning, drying and testing of the equipment prior to applying power. Thisrequires input and advice from the manufacturer. An area of particular concern is the maintenance ofthe dielectric properties of insulation. In the field application of medium voltage equipment, standoffinsulators are subjected to a wide variety of high voltage surges. Such insulators may needreplacement.

4.4 Transformers

Exposure of transformers to water can cause corrosion and insulation damage to the transformer coreand winding. The ability of the transformer to perform its intended function in a safe manner can also beimpaired by debris and chemicals, which may be deposited inside the transformer during a flood. Waterand contaminates will also damage the transformer fluids.

4.5 Wire, Cable and Flexible Cords

When any wire or cable product is exposed to water, any metallic component (such as the conductor,metallic shield, or armor) is subject to corrosion that can damage the component itself and/or causetermination failures. If water remains in medium voltage cable, it could accelerate insulationdeterioration, causing premature failure. Wire and cable listed for only dry locations may become ashock hazard when energized after being exposed to water.

Any recommendations for reconditioning wire and cable in Section 1.0 are based on the assumptionthat the water contains no high concentrations of chemicals, oils, etc. If it is suspected that the waterhas unusual contaminants, such as may be found in some floodwater, the manufacturer should beconsulted before any decision is made to continue using any wire or cable products.




4.6 AFCIs, Wiring Devices, Ground Fault Circuit Interrupters (GFCI)and Surge Protective Devices

Sediments and contaminants contained in water may migrate into the internal components of installedelectrical products and remain there even after the products have been dried or washed by the user.These may adversely affect the performance of those products without being readily apparent to theuser community. Also, electrical products, such as AFCIs, GFCIs and surge protective devices, containelectronic circuitry and other components, which can be adversely affected by water resulting in thedevice becoming non-functional or a hazard to the user. Air drying and washing of water damagedproducts of this type should not be attempted.

4.7 Cable Tray

Carefully inspect the cable tray system to determine if its mechanical and/or electrical integrity has beencompromised. Repair or replace any damaged portions per original installation requirements. Removeall debris from the cable tray. If any labels warning against the use of the cable tray as a walkway havebeen damaged, obtain new labels from the manufacturer and apply as required.

4.8 Luminaires (Lighting Fixtures) and Ballasts

Fluorescent, high-intensity discharge and incandescent luminaires are not intended for submersion inwater except for those that are listed as submersible luminaires. Flooded luminaires and associatedequipment may be damaged by corrosive materials, sediment, or other debris in the water. Corrosion ofmetallic parts and contamination of internal circuitry may prevent the equipment from operatingproperly.

4.9 Motors

Motors that have been flooded by water may be subjected to damage by debris or pollutants. This mayresult in damage to insulation, switches, contacts of switches, capacitors and overload protectors,corrosion of metallic parts, and contamination of the lubricating means and should be evaluated byqualified personnel.

4.10 Electronic Products, Including Signaling, Protection, Communication Systems andIndustrial Controls

Equipment used in signaling, protection and communication systems generally contain electroniccomponents, and the exposure of such equipment to flooding can adversely affect the reliability ofthose systems. Contamination by pollutants or debris in flood waters may cause corrosion ofcomponents of the system, shorting of printed circuits, or alteration of circuit characteristics. Sincesome of these types of installations are classified as life safety systems, it is important that the reliabilityof those systems be maintained.

Where such systems are damaged by water, replace components of these systems be replaced orreturned to the manufacturer for appropriate cleaning, recalibration, and testing. Manufacturers of these

systems should be contacted for information on specific equipment.

DISCLAIMER: The standards or guidelines presented in a NEMA standards publication are consideredtechnically sound at the time they are approved for publication. They are not a substitute for a productseller’s or user’s own judgment with respect to the particular product referenced in the standard orguideline, and NEMA does not undertake to guarantee the performance of any individualmanufacturer’s products by virtue of this standard or guide. Thus, NEMA expressly disclaims anyresponsibility for damages arising from the use, application, or reliance by others on the informationcontained in these standards or guidelines.

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NEMA_EvaluatingWater-DamagedElectricalEquipment